When a thermoplastic resin or a thermosetting resin is blended with inorganic fillers such as glass fibers, the resin can exhibit enhanced stiffness (flexural properties) such as flexural strength and flexural elasticity by virtue of inherent characteristics of the inorganic fillers. Commonly, blends of a thermoplastic resin such as polycarbonate and inorganic fillers are used for molded articles requiring high stiffness. Particularly, these blends having a flame retardant added thereto are widely used for interior/exterior materials of automobiles, electric/electronic products, and the like, which require flame retardancy, impact resistance, stiffness, and the like.
However, when the (flame retardant) thermoplastic resin is blended with inorganic fillers such as glass fibers, an overall resin composition can have deteriorated fluidity (moldability), and a molded article formed of the same can suffer from deterioration in appearance characteristics due to, for example, protrusion of the inorganic fillers from a surface of the article. In particular, when the resin composition (blend) is used for exterior materials of IT devices in which appearance characteristics are considered an important requirement, protrusion of the inorganic fillers has been regarded as a factor causing a main appearance quality issue. In addition, during injection molding, the resin composition can suffer from distortion due to anisotropy of the inorganic fillers. Accordingly, attempts have been made to use plate type talc, which can solve an anisotropy problem, as inorganic fillers (see Korean Patent Publication No. 2011-0059886).
However, when talc is used as the inorganic filler, usage of the resulting resin composition as exterior materials has limits since there is a concern of deterioration in mechanical properties of the resin composition, such as impact resistance (Izod impact strength), tensile elongation, and the like, due to brittleness of the talc.
In addition, although a thermoplastic resin composition can exhibit improved mechanical properties, impact resistance, and the like by combined use of inorganic fillers with coupling agents, compatibilizers, and the like, the resin composition can become brittle at room temperature with increasing amount of the inorganic fillers, and there is difficulty preventing deterioration in tensile elongation, fluidity, and the like. Moreover, unlike physical properties such as impact resistance and fluidity, it is difficult to improve flexural properties despite use of coupling agents, compatibilizers, and the like.
Therefore, there is a need for a thermoplastic resin composition that can exhibit excellent tensile elongation, flexural strength, flexural elasticity, impact resistance, fluidity, and balance therebetween.